JP4326759B2 - Process for producing 4-alkylphenols - Google Patents

Description

【００３４】
【表２】

【００３５】
【発明の効果】
本発明によれば、ｐ−アルキルフェノール類を収率よく工業的に有利に製造することができる。本発明により高純度のｐ−アルキルフェノール類を得ることができる。[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a method for producing 4-alkylphenols. 4-tert-butylphenol that obtained by the present invention (hereinafter, simply referred to as a 4-TBP) is useful as a raw material, such as molecular weight modifier, phenol resin, surfactants of the polycarbonate resin.
[0002]
[Prior art]
Conventionally, as a method for producing 4-alkylphenols, a method is known in which phenols and olefins or alcohols are reacted in the presence of a catalyst to alkylate the phenols. As a method for producing 4-alkylphenols from phenols and olefins, a method in which an olefin is added to phenols in the presence of an acid catalyst and then disproportionated is known (JP-A-8-12610). See the official gazette). In the case of this method, it is necessary to use a high-purity olefin in order to suppress the production of by-products derived from the raw material olefin. In particular, when using low-boiling olefins, it is difficult to obtain high-purity olefins by operations such as distillation, so the raw materials alcohols or ethers are purified, and dehydration or dealcoholization reactions are highly selective. And it is necessary to increase the purity to a desired level using a purification means such as distillation, which increases costs and is not economical. On the other hand, when alcohol is used as a raw material, there are advantages such as low preparation cost and easy handling compared to the case of using high-purity olefin.
[0003]
As a method for producing 4-alkylphenols by reacting phenols and alcohols in the presence of a catalyst, for example, (1) dehydration of activated clay, etc. under a pressure of 4 atm or less with secondary alcohol or tertiary alcohol with phenol A method of reacting while evaporating water in the presence of a condensation catalyst (see US Pat. No. 2,140,782), (2) tert-butanol having a water content of about 12 to 30% by weight (hereinafter referred to as TBA). And phenol in the presence of a synthetic silica / alumina catalyst (see JP-A-56-57727), (3) in the presence of a cation exchange resin. Method of alkylating phenol with TBA [Catalysis Letters, 19: 309-317 (1993) ) Reference] and the like are known.
[0004]
The activated clay used in the above method (1) has different properties depending on the production area, mining place, etc., and has poor reproducibility of catalytic activity. Since it is layered, water easily enters between layers, and the generated water reduces the catalytic activity. To do. Therefore, the method (1), it is necessary to evaporate water was distilled off from the reaction system, when using the TBA as A alcohol, TBA is to azeotrope with water, special to lower the water content of the activated clay Dehydration is required, which is economically disadvantageous. In the above method (2), since the proportion of ortho isomers rapidly increases at a temperature below 220 ° C., it is necessary to carry out the reaction at a high temperature, and it is carried out under pressure to maintain a liquid phase state. Therefore, a special pressure device is required. In the above method (3), there is a problem that the durability of the cation exchange resin at a high temperature is low and the post-treatment becomes complicated.
[0005]
In recent years, synthetic zeolite has attracted attention as a catalyst that is not only excellent in alkylating activity and selectivity of aromatic compounds, but also has no corrosive properties, little environmental pollution, and excellent durability. When alkylating phenol with TBA, as a method of using synthetic zeolite, for example, (4) a method of reacting in carbon tetrachloride in the presence of HY-type zeolite [Journal of Chemical Research (J) (J. Chem. Research) (S)), pp. 40-41 (1988)], (5) Method using large-diameter zeolite HY type or Hβ type [Applied Catalysis A: General, 166, 89-95] (1998) and 207, pp. 183-190 (2001)], (6) reaction in the gas phase using H-AlMCM-41, a mesoporous silicate [Microporous and Mesoporous and Mes. (Opological Materials), 39, 457-463 (2000)], (7) a method of reacting in silicoaluminophosphate molecular sieve SAPO-11 in the gas phase [Applied Catalysis A: Applied Catalysis A: General), 159, 229-240 (1997)].
[0006]
[Problems to be solved by the invention]
The contents of the literature describing the above methods (4) to (7) are all about the pore structure of the synthetic zeolite, properties such as acidity, temperature, feed rate of raw material, reaction conditions such as raw material ratio, etc. The effect on reaction selectivity was investigated, and an industrially advantageous method capable of producing 4-TBP with high yield was not examined. Moreover, the above method (4) not only has a low selectivity for 4-TBP, but also uses carbon tetrachloride as a solvent, and there is a concern about the influence on the environment. In the above method (5), since the oligomer of C4 hydrocarbon is produced, the yield of alkylphenol is low, and the selectivity of 4-TBP is also low. In the above methods (6) and (7), the catalytic activity is greatly deteriorated because the reaction is carried out in the gas phase.
[0007]
An object of the present invention is to provide an industrially advantageous method capable of producing 4-alkylphenols with high yield.
[0008]
[Means for Solving the Problems]
In the present invention, alcohols are reacted with 4-position unsubstituted phenols in the presence of synthetic zeolite at a temperature of 50 to 95 ° C., and then a rearrangement reaction is performed at a temperature of 105 to 150 ° C. in the obtained reaction mixture. It is the manufacturing method of 4-alkylphenol characterized.
[0009]
Oite this onset Ming, using phenol as the 4-position unsubstituted phenol, and the production of 4-TBP using TBA as the alcohol.
[0010]
DETAILED DESCRIPTION OF THE INVENTION
A feature of the present invention is that an alkylation reaction of 4-position unsubstituted phenols is carried out at a relatively low temperature in the range of 50 to 95 ° C., and then other than 4-alkylphenols contained in the obtained reaction mixture. By-products such as 2-alkylated phenols and 2,4-dialkylated phenols can be efficiently rearranged to 4-alkylphenols at a temperature in the range of 105 to 150 ° C. Due to such characteristics, the formation of oligomers of C4 hydrocarbons as seen in the above method (5) can be suppressed. Further, in the above temperature range, the reaction form is a liquid phase, and the deterioration of the catalyst as seen in the above methods (6) and (7) can be suppressed.
[0011]
Examples of the synthetic zeolite include large-diameter zeolite such as X-type, Y-type, β-type, L-type, and mordenite, medium-diameter zeolite represented by ZSM, SAPO, and the like, and mesoporous silicate represented by MCM and the like. Usually, a synthetic zeolite has exchangeable cations such as an alkali metal and an alkaline earth metal in the zeolite, and when used in the present invention, at least a part of the exchangeable cations is a transition metal ion, aluminum. Those exchanged with at least one ion selected from the group consisting of ions and protons are used.
[0012]
The synthetic zeolite used in the alkylation reaction is preferably one in which the zeolite has a low acidity, that is, a silica / alumina ratio, and the exchangeable cations of the zeolite are ion-exchanged with protons in order to increase the reaction efficiency. Moreover, in order to improve the selectivity of 4-alkylphenols, it is preferable to use a zeolite having pores corresponding to the molecular size of the 4-alkylphenols. For example, in the case of producing 4-TBP, it is preferable to use mordenite and β-type zeolite as the zeolite species, and the silica / alumina ratio is preferably in the range of 1 to 200, and in the range of 5 to 150. Are more preferable, and those in the range of 5 to 50 are particularly preferable.
[0013]
As the synthetic zeolite used in the rearrangement reaction, it is preferable to use a zeolite having pores corresponding to the molecular size of 4-alkylphenols in order to introduce an alkyl group at the 4-position of the phenols. Further, it is preferable that the zeolite has a low acidity (silica / alumina ratio) and the exchangeable cations of the zeolite are ion-exchanged with protons. If the synthetic zeolite has an acidity that is too high, the decomposition reaction is promoted and the selectivity to 4-alkylphenols tends to be low, which is not preferable. For example, when 4-TBP is produced, it is preferable to use Y-type zeolite as the zeolite species, and the silica / alumina ratio is preferably in the range of 1 to 200, and in the range of 5 to 150. More preferred are those with a range of 5-50.
[0014]
The synthetic zeolite used in the rearrangement reaction may be the same as or different from that used in the alkylation reaction. When performing the rearrangement reaction, the synthetic zeolite used in the alkylation reaction may be removed, or the rearrangement reaction may be performed without removal.
[0015]
The shape of the synthetic zeolite is not particularly limited, and powders, granules, lumps and the like can be used. Moreover, you may shape | mold and use the thing of a powder form and a granular form, and a spherical shape, a cylindrical shape, a ring shape, a star shape etc. are mentioned as a shape of a molded product, for example. The size of the synthetic zeolite particles is not particularly limited.
[0016]
The present invention can be carried out under normal pressure, reduced pressure, or increased pressure. The reaction mode may be batch or continuous. It can be carried out by a fixed bed system in which 4-position unsubstituted phenols and alcohol are passed through the synthetic zeolite, a fluidized bed system, and a moving bed system. The alkylation reaction and the rearrangement reaction in the present invention can be carried out in the same reactor or in successive reactors. It is also possible to subject the mixture obtained by the alkylation reaction to a rearrangement reaction after separating it from a solvent or the like. The amount of synthetic zeolite used varies depending on the reaction system, and in each reaction, for example, in the case of a batch system, it is preferably in the range of 1 to 100% by weight with respect to 4-position unsubstituted phenols, taking into account the reaction efficiency If it does, it is more preferable that it is the range of 5-25 weight%. When the amount of synthetic zeolite used is small, the reaction rate is slow, and when it is large, it is economically disadvantageous, which is not preferable in either case.
[0017]
4th As the unsubstituted phenols, phenol is used.
[0018]
The alcohol, T BA is used. The amount of alcohol used is preferably in the range of 0.2 to 2 mol, more preferably in the range of 0.3 to 1 mol, per mol of 4-position unsubstituted phenols.
[0019]
The alkylation reaction is carried out in the presence or absence of a solvent. The solvent is not particularly limited as long as it is inert to the reaction. For example, aliphatic hydrocarbons such as hexane, heptane, octane, nonane, decane, and cyclohexane; aromatic hydrocarbons such as benzene, toluene, xylene, and mesitylene; Halogenated hydrocarbons such as carbon tetrachloride, 1,2-dichloroethane and chlorobenzene are used. Among these, it is preferable to use toluene. The amount of the solvent to be used is not particularly limited, but it is preferably in the range of 1 to 20 times the weight with respect to the 4-position unsubstituted phenol considering the reaction efficiency, operability, economy and the like.
[0020]
The alkylation reaction is carried out at a relatively low temperature in the range of 50-95 ° C. When the reaction temperature is less than 50 ° C., the progress of the reaction becomes extremely slow and the residence time becomes long, so that the reaction efficiency tends to deteriorate. In addition, when the reaction temperature exceeds 95 ° C., not only the selectivity to the target 4-alkylphenol is lowered, but also the raw alcohol and 4-position unsubstituted phenol are polymerized to have a high boiling point. There is a tendency to by-produce compounds.
[0021]
The alkylation reaction time is preferably in the range of 1 to 30 hours, and more preferably in the range of 5 to 10 hours. When the residence time is less than 0.1 hour, the reaction does not proceed sufficiently and the reaction efficiency tends to be low, and when it exceeds 30 hours, a compound having a high boiling point tends to be by-produced. Yes, which is not preferable in either case.
[0022]
The rearrangement reaction is carried out in the presence or absence of a solvent. The solvent is not particularly limited as long as it is inert to the reaction. For example, aliphatic hydrocarbons such as heptane, octane, nonane, decane and methylcyclohexane; aromatic hydrocarbons such as toluene, xylene and mesitylene; chlorobenzene and the like Halogenated hydrocarbons are used. Among these, it is preferable to use toluene. The amount of the solvent to be used is not particularly limited, but it is preferably in the range of 1 to 20 times the weight with respect to the 4-position unsubstituted phenol considering the reaction efficiency, operability, economy and the like.
[0023]
The rearrangement reaction is carried out at a temperature in the range of 105 to 150 ° C. higher than the alkylation reaction temperature. If the reaction temperature is too high, the introduced alkyl group is decomposed to produce phenols as raw materials , so that the conversion rate of alkylated phenols decreases and the selectivity to p-alkylphenols decreases. There is a tendency. On the other hand, when the reaction temperature is too low, the rearrangement reaction rate is extremely slow, which tends to be economically disadvantageous.
[0024]
The rearrangement reaction time is preferably in the range of 1 to 20 hours from the viewpoint of suppressing the formation of by-products in the reaction and enhancing the effect of the rearrangement reaction.
[0025]
The 4-alkylphenols produced according to the present invention can be isolated and purified by a method used for the isolation and purification of ordinary organic compounds. For example, synthetic zeolite is filtered off from the reaction mixture as necessary, and the filtrate is subjected to operations such as distillation, recrystallization, and chromatography to isolate and purify 4-alkylphenols.
[0026]
【Example】
EXAMPLES The present invention will be specifically described below with reference to examples, but the present invention is not limited to these examples. In the table, 2-TBP represents 2-tert-butylphenol, and 2,4-DTBP represents 2,4-di-tert-butylphenol. The composition (%) after the reaction represents the area of each component obtained by gas chromatography analysis as a percentage. The 4-TBP selectivity (%) is expressed on a phenol basis, and the 4-TBP yield (%) is expressed on a TBA basis.
[0027]
Example 1
In a four-necked flask with an internal volume of 300 mL equipped with a stirrer, a condenser tube and a thermometer, phenol 50.0 g (531 mmol), Y-type zeolite substituted with protons (Tosoh Corporation, HSZ-331HSA) 12.5 g And 100 g of toluene was charged and stirred. The temperature was raised to 90 ° C., and 19.7 g (266 mmol) of TBA was added dropwise from a syringe over 3 hours. The alkylation reaction was performed by stirring at the same temperature for 2 hours. Then, it heated up to 120 degreeC and stirred for 3 hours, and rearrangement reaction (disproportionation) was performed. The reaction solution was analyzed by gas chromatography, and the phenol conversion, 4-TBP selectivity and yield were determined. The results are shown in Table 1.
[0028]
Example 2
A 100 mL four-necked flask equipped with a stirrer, condenser, and thermometer was charged with 50.0 g (531 mmol) of phenol and 12.5 g of Y-type zeolite substituted with protons (as described above) and stirred. . The temperature was raised to 90 ° C., and 19.7 g (266 mmol) of TBA was added dropwise from a syringe over 3 hours. The mixture was stirred at the same temperature for 2 hours to carry out an alkylation reaction. Then, it heated up to 120 degreeC and stirred for 3 hours, and rearrangement reaction (disproportionation) was performed. The reaction solution was analyzed by gas chromatography, and the phenol conversion, 4-TBP selectivity and yield were determined. The results are shown in Table 1.
[0029]
Example 3
A 100 mL four-necked flask equipped with a stirrer, a condenser and a thermometer was charged with 50.0 g (531 mmol) of phenol and 12.5 g of mordenite (HSZ-640HOA, manufactured by Tosoh Corporation) substituted with protons. , Stirred. The temperature was raised to 90 ° C., and 19.7 g (266 mmol) of TBA was added dropwise from a syringe over 3 hours. The mixture was stirred at the same temperature for 2 hours to carry out an alkylation reaction. Thereafter, mordenite substituted with protons was removed by filtration.
[0030]
A 100 mL four-necked flask equipped with a stirrer, condenser and thermometer was charged with 12.5 g of mordenite (as described above) substituted with the filtrate and proton obtained above, and the temperature was raised to 120 ° C. Then, a rearrangement reaction (disproportionation) was performed by stirring for 3 hours. The reaction solution was analyzed by gas chromatography, and the phenol conversion rate, 4-TBP selectivity and yield were determined. The results are shown in Table 2.
[0031]
Example 4
Beta-zeolite substituted with 50.0 g (531 mmol) of phenol and proton in a four-necked flask with an internal volume of 100 mL equipped with a stirrer, a condenser and a thermometer (manufactured by Sued Chemie, H-BEA-25) 12.5 g was charged and stirred. The temperature was raised to 90 ° C., and 19.7 g (266 mmol) of TBA was added dropwise from a syringe over 3 hours. The mixture was stirred at the same temperature for 2 hours to carry out an alkylation reaction. Thereafter, the β-type zeolite substituted with protons was removed by filtration.
[0032]
A 100 mL four-necked flask equipped with a stirrer, condenser and thermometer was charged with 12.5 g of mordenite (as described above) substituted with the filtrate and proton obtained above, and the temperature was raised to 120 ° C. Then, a rearrangement reaction (disproportionation) was performed by stirring for 3 hours. The reaction solution was analyzed by gas chromatography, and the phenol conversion, 4-TBP selectivity and yield were determined. The results are shown in Table 2.
[0033]
[Table 1]

[0034]
[Table 2]

[0035]
【The invention's effect】
According to the present invention, p-alkylphenols can be advantageously produced industrially with good yield. According to the present invention, highly pure p-alkylphenols can be obtained.

Claims (1)

4) An alcohol is reacted with 4-position unsubstituted phenols in the presence of synthetic zeolite at a temperature of 50 to 95 ° C., and then a rearrangement reaction is performed at a temperature of 105 to 150 ° C. in the obtained reaction mixture. -Method for producing alkylphenols , wherein the 4-position unsubstituted phenols are phenol and the alcohol is tert-butanol .